Many
Frankie fans would have noticed that Thelonius sounded very familiar.

That
might be because Frankie supplied the voice for a nerd Lisa meets and falls in
love with on a very confusing Simpsons episode.

Here
is a detailed description of the episode:

Three,
intertwining tales offer different perspectives on a day in the life of the
Simpsons. First, Homer's attempt to steal a freshly baked brownie results in
Marge accidentally cutting off his thumb. They must race to the hospital to have
it reattached.

In
the meantime, Lisa can't find her bike and is left without a ride to school, on
the day of the big science fair. Her invention, a robot that corrects grammar,
can't win first prize unless she enters on time. At one point she finds herself
at West Springfield Elementary, where she meets Thelonius (Frankie Muniz). The
two spin in a circle for a while, then Lisa realises the time and goes. In
her numerous attempts to get to school, she eventually crosses paths with the
rest of the family.

Meanwhile,
Bart and Millhouse uncover a stash of fireworks. When Chief Wiggum catches up to
them, he enlists their help in an undercover sting operation, with explosive
results. As the mayhem of the day unfolds, it becomes clear how the actions of
each family member directly affects the rest of the household.